Minimum infective dose of Mycobacterium bovis in cattle
Minimum infective dose of Mycobacterium bovis in cattle
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DOI：
10.1128/iai.73.10.6467-6471.2005
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发表时间：
2005-10-01
影响因子：
3.1
通讯作者：
Vordermeier, HM
中科院分区：
文献类型：
--
作者：
Dean, GS;Rhodes, SG;Vordermeier, HM
这项工作的目的是确定牛分枝杆菌刺激特异性免疫反应和产生病理所需的最小感染剂量。用1，000、100、10或1 CFU的M通过肠道途径感染4组小牛（20只动物）。牛在整个研究过程中监测对分枝杆菌抗原的特异性免疫应答（γ干扰素[IFN-γ]和白细胞介素-4 [IL-4]应答），并分两次评估对结核菌素皮肤试验的应答。进行严格的尸检以确定病理学的存在，并采集样本用于M的微生物和组织病理学确认。牛传染病半数动物感染1 CFU M.牛出现了典型的牛结核病的肺部病理。对于不同的M，未观察到病理学严重程度的差异。牛剂量。所有发生病理学的动物均为皮肤试验阳性，并产生特异性IFN-γ和IL-4应答。对于不同的M，在皮肤试验反应的大小、达到阳性IFN-γ结果所需的时间或IFN-γ和IL-4应答的水平方面没有观察到差异。牛剂量，表明诊断测定（结核菌素皮肤试验和IFN-γ试验）可以检测牛后不久M。无论剂量如何，牛感染。这些信息应该是有用的牛结核病在牛的动力学建模和传播的风险评估。
The aim of this work was to determine the minimum infective dose of Mycobacterium bovis necessary to stimulate specific immune responses and generate pathology in cattle. Four groups of calves (20 animals) were infected by the intratracheal route with 1,000, 100, 10, or 1 CFU of M. bovis. Specific immune responses (gamma interferon [IFN-gamma] and interleukin-4 [IL-4] responses) to mycobacterial antigens were monitored throughout the study, and the responses to the tuberculin skin test were assessed at two times. Rigorous post mortem examinations were performed to determine the presence of pathology, and samples were taken for microbiological and histopathological confirmation of M. bovis infection. One-half of the animals infected with 1 CFU of M. bovis developed pulmonary pathology typical of bovine tuberculosis. No differences in the severity of pathology were observed for the different M. bovis doses. All animals that developed pathology were skin test positive and produced specific IFN-gamma and IL-4 responses. No differences in the sizes of the skin test reactions, the times taken to achieve a positive IFN-gamma result, or the levels of the IFN-gamma and IL-4 responses were observed for the different M. bovis doses, suggesting that diagnostic assays (tuberculin skin test and IFN-gamma test) can detect cattle soon after M. bovis infection regardless of the dose. This information should be useful in modeling the dynamics of bovine tuberculosis in cattle and in assessing the risk of transmission.